added project start and end date (#1303)

* added sortable js library
* activity in invoice is optional
* added javascript widget for paginated boxes
* fix activity dropdown for globals only
* added timesheet service to reduce code duplication
* use repository to query for teams in dropdowns
* added project validator
* validate project start and end against timesheet
* include begin and end in dynamic form requests for projects
* added timezone and language option to import flag, improve timesheet import speed
* deactivate cross-timezone filter
* add virtual fields to field order list
* composer update
* added param to ignore dates
* position loader icon fixed - fixes #1330
* permission problem when creating a new project - fixes #1340
* remove dev dependencies webserver and thanks bundle
* stop information leak (begin and end date) in duration mode - fixes #1307
* unify timesheet edit dialog for user and admins
* fix security issue, own rates exposed to unauthorized users in multi-update dialog

translations/messages.en.xlf

@@ -358,7 +358,7 @@
             </trans-unit>
             <trans-unit id="label.my_team_projects">
                 <source>label.my_team_projects</source>
-                <target>Team Projects &amp; budgets</target>
+                <target>Team projects &amp; budgets</target>
             </trans-unit>
             <trans-unit id="label.progress">
                 <source>label.progress</source>
@@ -516,6 +516,14 @@
                     activities and %records% time-records, which sum up to a total of %duration%.
                 </target>
             </trans-unit>
+            <trans-unit id="label.project_start">
+                <source>label.project_start</source>
+                <target>Project start</target>
+            </trans-unit>
+            <trans-unit id="label.project_end">
+                <source>label.project_end</source>
+                <target>Project end</target>
+            </trans-unit>
 
             <!--
               Admin: Activity